Restrictive Respiratory Dysfunction Research Articles

The Clinical Approach to Interstitial Lung Disease in Childhood: A Narrative Review Article.

Interstitial lung disease (ILD) comprises a group of respiratory diseases affecting the interstitium of the lungs, which occur when a lung injury triggers an abnormal healing response, and an inflammatory process leads to altered diffusion and restrictive respiratory dysfunction. The term "interstitial" may be misleading, as other components of the lungs are usually also involved (epithelium, airways, endothelium, and so on). Pediatric conditions (childhood interstitial lung disease, chILD) are different from adult forms, as growing and developing lungs are affected and more diverse and less prevalent diseases are seen in childhood. Diffuse parenchymal lung disease (DPLD) and diffuse lung disease (DLD) can be used interchangeably with ILD. Known etiologies of chILD include chronic infections, bronchopulmonary dysplasia, aspiration, genetic mutations leading to surfactant dysfunction, and hypersensitivity pneumonitis due to drugs or environmental exposures. Many forms are seen in disorders with pulmonary involvement (connective tissue disorders, storage diseases, malignancies, and so on), but several conditions have unknown origins (desquamative pneumonitis, pulmonary interstitial glycogenosis, neuroendocrine cell hyperplasia in infancy, and so on). Currently, there is no consensus on pediatric classification; however, age grouping is proposed as some specific forms are more prevalent in infancy (developmental and growth abnormalities, surfactant dysfunction mutations, etc.) and others are usually seen in older cohorts (disorders in normal or immunocompromised hosts, systemic diseases, etc.). Clinical manifestations vary from mild nonspecific symptoms (recurrent respiratory infections, exercise intolerance, failure to thrive, dry cough, etc.) to a severe clinical picture (respiratory distress) and presentation related to the child's age. The diagnostic approach relies on imaging techniques (CT), but further investigations including genetic tests, BAL, and lung biopsy (VATS) are needed in uncertain cases. Pharmacological treatment is mostly empiric and based on anti-inflammatory and immunomodulatory drugs. Lung transplantation for selected cases in a pediatric transplantation center could be an option; however, limited data and evidence are available regarding long-term survival. International collaboration is warranted to understand chILD entities better and improve the outcomes of these patients.

Biallelic variants in SNUPN cause a limb girdle muscular dystrophy with myofibrillar-like features.

Alterations in RNA-splicing are a molecular hallmark of several neurological diseases, including muscular dystrophies, where mutations in genes involved in RNA metabolism or characterized by alterations in RNA splicing have been described. Here, we present five patients from two unrelated families with a limb-girdle muscular dystrophy (LGMD) phenotype carrying a biallelic variant in SNUPN gene. Snurportin-1, the protein encoded by SNUPN, plays an important role in the nuclear transport of small nuclear ribonucleoproteins (snRNPs), essential components of the spliceosome. We combine deep phenotyping, including clinical features, histopathology and muscle MRI, with functional studies in patient-derived cells and muscle biopsies to demonstrate that variants in SNUPN are the cause of a new type of LGMD according to current definition. Moreover, an in vivo model in Drosophila melanogaster further supports the relevance of Snurportin-1 in muscle. SNUPN patients show a similar phenotype characterized by proximal weakness starting in childhood, restrictive respiratory dysfunction and prominent contractures, although inter-individual variability in terms of severity even in individuals from the same family was found. Muscle biopsy showed myofibrillar-like features consisting of myotilin deposits and Z-disc disorganization. MRI showed predominant impairment of paravertebral, vasti, sartorius, gracilis, peroneal and medial gastrocnemius muscles. Conservation and structural analyses of Snurportin-1 p.Ile309Ser variant suggest an effect in nuclear-cytosol snRNP trafficking. In patient-derived fibroblasts and muscle, cytoplasmic accumulation of snRNP components is observed, while total expression of Snurportin-1 and snRNPs remains unchanged, which demonstrates a functional impact of SNUPN variant in snRNP metabolism. Furthermore, RNA-splicing analysis in patients' muscle showed widespread splicing deregulation, in particular in genes relevant for muscle development and splicing factors that participate in the early steps of spliceosome assembly. In conclusion, we report that SNUPN variants are a new cause of limb girdle muscular dystrophy with specific clinical, histopathological and imaging features, supporting SNUPN as a new gene to be included in genetic testing of myopathies. These results further support the relevance of splicing-related proteins in muscle disorders.

Respiratory pathology in a patient with muscular dystrophy

Abstract Duchenne muscular dystrophy (DMD) is a genetic neuromuscular disorder with X-linked inheritance, characterised by progressive motor deficit, causing loss of the ability to walk and multisystemic complications. Currently, there is no known aetiologic treatment for DMD which seeks to remove or correct its cause. Progressive respiratory muscle damage associates thoracic deformities, and ineffective cough, which leads to significant complications such as hypoventilation, nocturnal desaturation and chronic respiratory failure. Respiratory impairment represents the major cause of mortality in patients with muscular dystrophy. This highlights the importance of early and correct management of this illness. We present the case of a 17-year-old patient, genetically diagnosed with DMD at the age of 5 years that became non-ambulant at the age of 12. He had complications such as iatrogenic Cushing syndrome, anxiety, depressive disorder, mild cardiac dysfunction, severe restrictive respiratory dysfunction, nocturnal hypercapnia and sleep apnoea syndrome treated with BiLevel Positive Airway Pressure Spontaneous/Timed Therapy (BiPAP-ST). In evolution, it was decided to perform a tracheostomy and quasi-permanent ventilation. The clinical and paraclinical presentation of this patient is typical of that of an advanced stage of DMD, with progressive aggravation in the past years, despite the correct multidisciplinary management, following the international care standard of this disease. The particularity of the case is based on the complexity of all the comorbidities associated with the disease and the impact they have on the mental health of the patient, leading to the degradation of his general state. Having limited respiratory function, the patient died secondary to a tracheostomy tube complication. These complications represent a major cause of mortality in patients with neuromuscular disorders. An early and correct management of the respiratory tract pathology of these patients is essential for improving their quality of life and increasing their life span.

Parkinson's induced severe restrictive respiratory dysfunction for deep brain stimulation - Anaesthesiologists' perspective.

Parkinson's induced severe restrictive respiratory dysfunction for deep brain stimulation - Anaesthesiologists' perspective.

The impact of new bronchial drainage device in a complex form of respiratory disease

Abstract Drainage of secretions in patients with severe lung damage is a challenge. In many cases, due to the significant reduction in muscle mass, difficulties of this nature arise. We present the case of an 82-year-old patient, vaccinated against Severe acute respiratory syndrome coronavirus 2 (SARS COV2), anti-influenza, anti-pneumococcal and anti-haemophilus, former smoker, with no significant exposure to known professional respiratory noxes, with severe comorbidities (cardiac, ophthalmological, rheumatological, neurological, and diabetological) and a congenital pulmonary malformation – right lung hypoplasia (diagnosed in 2008), extensive cystic and varicose bronchiectasis, probably also in a congenital context, with progressive collapse of the right parenchyma and displacement of the mediastinum, complicated with recurrent respiratory infectious episodes with pathogens – Gram-negative germs, anaerobic germs, and repetitive low-amount haemoptysis for 3 years, as well as severe restrictive respiratory dysfunction. Currently, the patient is under bronchodilator treatment, and home oxygen therapy. For about 3 years, regular modern drainage sessions using the studied device have been introduced. Patient adherence was good. The benefits brought by this device on the clinical development of the patient were: efficient drainage of secretions, improvement of the quality of life, and prolongation of survival in a patient with complex pulmonary pathology and multiple comorbidities in development for 13 years. This new therapeutic drainage option has been competing with pre-existing ways (Cough Assist) for several years, demonstrating its multiple benefits in patients with chronic respiratory failure and severe comorbidities.

Prevalence of chronic post-thoracotomy pain in patients with traumatic multiple rib fractures in South Korea: a cross-sectional study

Chronic post-thoracotomy pain is a debilitating condition after traumatic multiple rib fractures and surgery. We aimed to estimate the prevalence of chronic post-thoracotomy pain after traumatic multiple rib fractures in South Korea and explore factors associated with it. From October 2017 to June 2019, a cross-sectional survey of 100 adults, who had undergone thoracotomy due to traumatic fractures of two or more ribs 2 years to 3 months prior to the survey, was conducted in the regional trauma center in South Korea. In total, 80% and 65% patients reported any level and above moderate chronic pain, respectively. Quality of life was mostly below the normative value of the US general population. Forty-six percent patients had restrictive respiratory dysfunction, and 47% and 59% patients were classified as being at risk of above mild-level anxiety and depression, respectively. More than 70% of patients had a current opioid prescription. Multivariable logistic regression analysis showed weak evidence of association between acute, severe postoperative pain and chronic postsurgical pain (adjusted odds ratio 2.4, 95% confidence intervals 0.9 to 6.4). Collectively, chronic post-thoracotomy pain and associated incomplete recovery regarding respiratory, functional, and psychological outcomes were prevalent in patients with traumatic multiple rib fractures in South Korea.

Successful Airway and Anesthesia Management Using a High-Flow Nasal Cannula in a Fibrodysplasia Ossificans Progressiva Patient During General Anesthesia: A Case Report

Fibrodysplasia ossificans progressiva (FOP) is a rare hereditary disorder causing neck stiffness, ankylosis of temporomandibular joints, and severe restrictive respiratory dysfunction due to progressive heterotopic ossification of the connective tissue. Herein, we report a case of successful airway and anesthesia management using a high-flow nasal cannula (HFNC) in a 51-year-old man with FOP undergoing partial bone resection of the right greater trochanter of the femur. Although general anesthesia with awake fiberoptic nasotracheal intubation has been described as the gold standard, HFNC may yield another potentially viable option for patients undergoing a surgical procedure that does not involve the airway.

Talasemi major hastalarında asemptomatik solunum fonksiyon bozukluğu

Purpose: Regular transfusions cause progressive iron deposition in critical organs such as heart, liver and lungs in transfusion-dependent thalassemia (TDT). We aimed to evaluate respiratory dysfunction and factors affecting respiratory dysfunction in patients with TDT.Materials and Methods: Patients with TDT treated at department of Pediatric Hematology/Oncology of Sağlık Bilimleri University, Adana Education and Research Center were evaluated retrospectively. Results: Respiratory function tests were performed in 40 patients (19 female; 21 male) with TDT. The mean age at diagnosis was 6.63±5.74 months, mean body mass index was 18.57±2.27 kg/m², mean transfusion program duration was 151.67±50.48 months. Splenectomy rate was 48%. All of the patients were using iron chelation therapy. Respiratory function tests reveled normal findings in 57.5%, restrictive lung dysfunction with small airway obstruction findings in 27.5% and isolated restrictive dysfunction in 15% of patients. There was no statistically significant difference in respiratory dysfunction according to age, gender, transfusion program duration, ferritin and hemoglobin levels, presence of splenectomy, or type of chelation therapy. Patients with ferritin levels above 2500 ng/dl had significantly lower values for forced expiratory volüme (FEV1) and forced vital capacity (FVC) Conclusion: In our study, restrictive respiratory dysfunction was detected in nearly half of the patients with TDT who had no respiratory symptoms. Higher ferritin levels may indicate the need for close follow-up for respiratory symptoms.

Effects of PM2.5 on Cardio-Pulmonary Function Injury in Open Manganese Mine Workers.

Exposure to fine particulate matter 2.5 (PM2.5) is associated with adverse health effects, varying by its components. The health-related effects of PM2.5 exposure from ore mining may be different from those of environment pollution. The aim of this study was to investigate the effects of different concentrations of PM2.5 exposure on the cardio-pulmonary function of manganese mining workers. A total of 280 dust-exposed workers who were involved in different types of work in an open-pit manganese mine were randomly selected. According to the different concentrations of PM2.5 in the working environment, the workers were divided into an exposed group and a control group. The electrocardiogram, blood pressure, and multiple lung function parameters of the two groups were measured and analyzed. The PM2.5 exposed group had significantly lower values in the pulmonary function indexes of forced expiratory volume in one second (FEV1.0), maximum mid expiratory flow (MMEF), peak expiratory flow rate (PEFR), percentage of peak expiratory flow out of the overall expiratory flow volume (PEFR%), forced expiratory flow at 25% and 75% of forced vital capacity (FEF 25, FEF75), forced expiratory flow when 25%, 50%, and 75% of forced vital capacity has been exhaled (FEF25%,FEF50%, FEF75%), and FEV1.0/FVC% (the percentage of the predicted value of forced vital capacity) than the control group (all p < 0.05). Both groups had mild or moderate lung injury, most of which was restrictive ventilatory disorder, and there was significant difference in the prevalence rate of restrictive respiratory dysfunction between the two groups (41.4% vs. 23.6%, p = 0.016). Electrocardiogram (ECG) abnormalities, especially sinus bradycardia, were shown in both groups, but there was no statistical difference of the prevalence rate between the two groups (p > 0.05). Also, no significant difference of the prevalence rate of hypertension was observed between the PM2.5 exposure and control groups (p > 0.05). PM2.5 exposure was associated with pulmonary function damage of the workers in the open-pit manganese mine, and the major injury was restrictive ventilatory disorder. The early effect of PM2.5 exposure on the cardiovascular system was uncertain at current exposure levels and exposure time.

Usefulness of transcutaneous PCO2 to assess nocturnal hypoventilation in restrictive lung disorders.

Nocturnal hypoventilation is now an accepted indication for the initiation of non-invasive ventilation. Nocturnal hypoventilation may be an under diagnosed condition in chronic respiratory failure. The most appropriate strategy to identify sleep hypoventilation is not yet clearly defined. In clinical practice, it is indirectly assessed using nocturnal pulse oximetry (NPO) and morning arterial blood gases (mABG). Even though continuous transcutaneous carbon dioxide partial pressure (TcPCO2 ) monitoring is theoretically superior to NPO plus mABG, it is not routinely used. We aimed to prospectively compare NPO plus mABG with nocturnal TcPCO2 for the detection of alveolar hypoventilation in a cohort of patients with chronic restrictive respiratory dysfunction. We assessed 80 recordings of mABG, nocturnal TcPCO2 and NPO in 72 consecutive patients with neuromuscular disease or thoracic cage disorders. Nocturnal hypoventilation was defined as a mean nightime TcPCO2 ≥50 mm Hg, and nocturnal hypoxaemia as ≥30% of the night with transcutaneous pulse oxygen saturation ≤90% and/or >5 consecutive minutes with transcutaneous pulse oxygen saturation ≤88%. Amongst the 80 recordings, 25 of 76 (32.9%) without nocturnal hypoxaemia and 16 of 59 (27.1%) without hypercapnia on mABG showed nocturnal hypoventilation on TcPCO2 . Amongst recordings showing both normal NPO and mABG, 16 of 52 (30.8%) had a mean TcPCO2 ≥50 mm Hg. Nocturnal hypoxaemia was associated with nocturnal hypoventilation in all recordings. However, 5 of 21 (23.8%) recordings that showed an absence of nocturnal hypoventilation at the chosen threshold showed hypercapnia on mABG. Morning arterial blood gases and NPO alone or in combination underestimate nocturnal hypoventilation in patients with chronic restrictive respiratory dysfunction of extrapulmonary origin.

Respiratory dysfunction in Charcot-Marie-Tooth disease type 1A.

We aimed to investigate the relationship between neurological compromise, respiratory parameters in wakefulness and in sleep, physiology, and morphology of phrenic nerves in patients with Charcot-Marie-Tooth disease type 1A (CMT1A). Sixteen patients with CMT1A were evaluated by spirometry, maximal expiratory and maximal inspiratory pressures (MEP, MIP), polysomnography, phrenic nerve compound muscle action potential (CMAP), and ultrasonography (roots C3,C4,C5 and phrenic nerves). Clinical disability was measured with Charcot-Marie-Tooth neuropathy score (CMT-NS; range 0-36). Two control groups, comprising 30 individuals matched for age, sex, and body mass index, were used for comparison. Ten patients were female (62%), mean age was 37.88 years (range 24-76); and CMT-NS range was 7-34. MIP was reduced in five (31%) and MEP in 12 patients (75%), although only one had restrictive respiratory dysfunction in spirometry. Apnoea-hypopnea index (AHI) was significantly higher in patients (12.01 ± 11.57/h × 5.89 ± 8.36/h; p value = 0.05) and increased in REM sleep compared with NREM (9.94 ± 10.96/h × 19.13 ± 19.93/h; p value = 0.01). There were significant correlations between CMT-NS and AHI (Pearson = 0.69; p value = 0.03); CMT-NS and MIP (Pearson = -0.691, p value = 0.003); and CMT-NS and MEP (Pearson = -0.603, p value = 0.013). Also, AHI showed negative correlation with MIP (Pearson = -0.52, p value = 0.036) and MEP (Pearson = -0.55, p value = 0.026). Phrenic nerves were enlarged in ultrasonography in all patients and presented significant correlations with CMAPs (right: Pearson = -0.554, p value = 0.026; left: Pearson = -0.558, p value = 0.025). We suggest that axonal degeneration of nerves directed to muscles of respiration might explain the high prevalence of respiratory weakness in patients with CMT1A. Clinical manifestations are frequent during sleep, where the diaphragm alone can only partially surpass the overload in breathing apparatus.

P.1.1 Natural history of Ullrich congenital muscular dystrophy

Ullrich congenital muscular dystrophy (UCMD) is the second most common CMD in Japan. Mutations in either <i>COL6A1</i>, <i>COL6A2</i>, or <i>COL6A3</i> gene, each encoding a subunit of collagen VI (COL6) are known to cause UCMD. To date, there is no cure for this disease and only limited information on the rate of disease progression. To characterize the natural history of UCMD, questionnaire-based nationwide survey was conducted from October 2010 to February 2011. We enrolled 33 patients (age at survey, 11.0±6.6years (mean±SD)) with COL6 deficiency on immunohistochemistry in skeletal muscle: 5with complete and 28 with sarcolemma specific COL6 deficiency. Sequence analysis of <i>COL6</i> genes was performed using genomic DNA from 32 patients, 19 (59.4%) of whom carried identifiable mutations. We analyzed the information on perinatal and developmental abnormalities, clinical manifestations, data of Cobb angle and % vital capacity (%VC). Age at muscle biopsy was 3.2±2.0years. Creatine kinase level was 315±110 (IU/L) (<i>n</i>=31). Twenty-five (81%) of 31 patients walked independently by age 1.7±0.5years but lost this ability by age 8.8±2.9years (<i>n</i>=11). Six patients never walked independently. %VC was decreased exponentially with age, resulting in severe respiratory dysfunction before pubescence. Noninvasive ventilation was initiated at age 11.2±3.6years (<i>n</i>=13). Cobb angle over 30° was noted at age 9.9±5.3years (<i>n</i>=17). The maximum progression rate was 16.2±10.0°/year (<i>n</i>=13). Scoliosis surgery was performed in 3 patients at respective ages 5, 9 and 10years. Postoperative %VC was relatively well maintained in the youngest patient. The natural history of walking ability, respiratory function and scoliosis in UCMD patients was characterized. Although the age of onset varied, scoliosis, as well as restrictive respiratory dysfunction, progressed rapidly within years, once they appeared.

Rapidly progressive scoliosis and respiratory deterioration in Ullrich congenital muscular dystrophy

ObjectiveTo characterise the natural history of Ullrich congenital muscular dystrophy (UCMD).Patients and methodsQuestionnaire-based nationwide survey to all 5442 certified paediatric and adult neurologists in Japan was conducted from October 2010...

Vocal cord paresis and diaphragmatic dysfunction are severe and frequent symptoms of GDAP1-associated neuropathy

Cranial nerve involvement in Charcot-Marie-Tooth disease (CMT) is rare, though there are a number of CMT syndromes in which vocal cord paralysis is a characteristic feature. CMT disease due to mutations in the ganglioside-induced differentiation-associated protein 1 gene (GDAP1) has been reported to be associated with vocal cord and diaphragmatic palsy. In order to address the prevalence of these complications in patients with GDAP1 mutations we evaluated vocal cord and respiratory function in nine patients from eight unrelated families with this disorder. Hoarseness of the voice and inability to speak loudly were reported by eight patients and one had associated symptoms of respiratory insufficiency. Patients were investigated by means of peripheral and phrenic nerve conduction studies, flexible laryngoscopy, pulmonary function studies and polysomnography. Nerve conduction velocities and pathological studies were compatible with axonal CMT (CMT2). Flexible laryngoscopy showed left vocal cord palsy in four cases, bilateral cord palsies in four cases and was normal in one case. Restrictive respiratory dysfunction was seen in the eight patients with vocal cord paresis who were all chair-bound. These eight had confirmed phrenic nerve dysfunction on neurophysiology evaluation. The patient with normal vocal cord and pulmonary function had a less severe clinical course.This study shows that CMT patients with GDAP1 mutations develop severe disability due to weakness of limb muscles and that laryngeal and respiratory muscle involvement occurs late in the disease process when significant proximal upper limb weakness has developed. The early and predominant involvement of the left vocal cord innervated by the longer left recurrent laryngeal nerve suggests a length dependent pattern of nerve degeneration. In GDAP1 neuropathy, respiratory function should be thoroughly investigated because life expectancy can be compromised due to respiratory failure.

Diagnosis of myotubular myopathy in the oldest known manifesting female carrier: A clinical and genetic study

X-linked myotubular myopathy is a congenital myopathy due to mutation in the MTM1 gene, encoding myotubularin. Most of the affected male neonates die early of respiratory failure. The female carriers are usually asymptomatic. The authors report a novel MTM1 mutation in a 77-year-old woman. She presented with progressive ptosis since childhood, proximal limb weakness, and a severe restrictive respiratory dysfunction with a hemidiaphragmatic paresis, leading to death at 84 years of age. The muscle biopsy showed centrally nucleated fibers and mitochondrial abnormalities. A stop mutation Leu498X in MTM1 gene was identified in the proband and in her two healthy daughters. The X-inactivation pattern was random in the proband’s blood and muscle DNA, and in blood DNA from her two unaffected MTM1 mutation carrier daughters. Two large heteroplasmic deletions were also detected in the muscle mitochondrial DNA of the propositus, raising the question of their putative impact on the phenotype.

Scoliosis Correction in an Adolescent with a Rigid Spine Syndrome

Details of presentation and approach to the treatment of scoliosis in a case of a Rigid Spine Syndrome (RSS). To report on the results of conservative and operative treatment of scoliosis associated with RSS, and, based on this, to propose an assessment and treatment protocol for this condition. Congenital muscular dystrophies (CMD) are a group of disorders marked by hypotonia at birth and a generally nonprogressive course of muscle weakness. Spinal rigidity is present in a number of patients with CMD. RSS is classified as a CMD, and is characterized by early rigidity of the spine, limb contractures, and restrictive respiratory dysfunction. An approach to the treatment of scoliosis in RSS has not been established. Details of history, diagnostic tests, and treatment of an adolescent with RSS associated with progressive scoliosis and cervical spine extension contracture is presented. The role of brace treatment, Botox (Allergan, Inc., Irvine, CA), and details of operative correction, including histology of back muscles, is defined. In this case of RSS with rigid scoliosis nonresponsive to brace therapy and Botox injections, an anterior thoracolumbar spine fusion with instrumentation was successfully performed for correction of the scoliosis, and the cervical spine was addressed through a posterior approach and an occiput-cervical fusion. We outline the details of surgical procedure and restoration of spinal balance in both sagittal and coronal planes. The chromosomal bases of CMD and characteristic features of RSS, including diagnostic tests, have been reviewed. Surgical intervention with spinal deformity fusion, correction, and instrumentation is indicated in RSS with progressive spinal imbalance not responding to conservative therapy is safe and can give promising results.

Late Postoperative Respiratory Function in Adults After Surgical Correction of Atrial Septal Defects: Analysis of Respiratory Dysfunction Patterns

Respiratory function after repair of atrial septal defect (ASD) was analysed in 44 adults (>40 years), 21 of whom had preoperative respiratory dysfunction, 14 of restrictive type, defined as % vital capacity (%VC) less than 80% of predicted value, 3 with an obstructive pattern, defined as % forced expiratory volume/1 s (%FEV1) less than 70% of predicted value, and 4 patients with a mixed pattern. Increased %VC was found postoperatively in all 14 patients with restrictive respiratory dysfunction, with normal values in 8 out of the 14. Although the three patients with obstructive, and the four with mixed-pattern respiratory dysfunction improved preoperatively in %VC or %FEV1, or both, none had normalized values. We conclude that preoperative restrictive respiratory dysfunction in ASD patients frequently normalizes postoperatively, but not dysfunction of obstructive or mixed restrictive-obstructive type.

Lung volumes in tetraplegic patients according to cervical spinal cord injury level

Fifty-six tetraplegic patients with motor complete lesions (Frankel A and B) underwent spirometric measurements more than 6 months after injury. The results were evaluated according to the level of transection of the cervical cord. A pronounced restrictive respiratory dysfunction was demonstrated in all patients. The expiratory reserve volume (ERV) was zero or markedly reduced in patients at all lesion levels. Systematic increases in both ERV and vital capacity (VC) were found with lower lesion level. The inspiratory capacity (IC) was reduced at all injury levels, but there were no systematic differences in IC between injury levels C4-C8. The total lung capacity (TLC) was reduced and the ratio residual volume/total lung capacity (RV/TLC) was increased in patients at all injury levels. The lung function of patients tested &gt; 12 months after injury was not significantly different from the function in those tested 6-12 months after injury. A respiratory rehabilitation programme for tetraplegic patients should take into account the fact that the respiratory function, especially the forced expiration, is dependent upon injury level.

Rigid spine syndrome with respiratory failure.

The pathogenesis and therapy of respiratory failure in the rigid spine syndrome are discussed in two cases who improved with respiratory assistance. In both cases, the partial pressures of oxygen and carbon dioxide were reversed in arterial blood gas analysis and %VC was less than 30%. Remission from respiratory failure has been obtained by the use of a ventilator during the night. The cause of the respiratory failure in both cases was severe restrictive respiratory dysfunction due to extreme flattening of the chest and fixation of the thorax during respiration as a result of contracture of costovertebral joints. All the previously reported cases of the rigid spine syndrome with respiratory failure died. Appropriate use of the ventilator can improve the prognosis.

Lung function in patients with prior poliomyelitis

Lung volumes and spirometric flows, maximal respiratory pressures, lung diffusion capacity and blood gases were evaluated in 20 patients with prior poliomyelitis and compared with data from an age- and sex-matched control group. In the polio patients, static lung volumes and pulmonary flow capacity were significantly reduced to approximately 65% of the values of the control group. However, expiratory and inspiratory flows were normal in relation to lung volumes, while maximal respiratory pressures were significantly reduced in the polio patients. Static lung volumes and forced flows were correlated with the maximal respiratory pressures both in the polio patients and in the controls. However, when the muscle force in the polio patients decreased below a certain level, it became more important as a determinant of lung-flow capacity. The polio patients had a significantly increased PCO2 but a normal oxygen saturation and PCO2 was inversely correlated with the maximal respiratory pressures in the patients but not in the controls. The lung diffusion capacity was reduced in the polio patients compared to the controls, but less markedly than vital and total lung capacity. The findings indicate a restrictive respiratory dysfunction and alveolar hypoventilation most probably due to weakness of the respiratory muscles.